Book rack



FIG. 1 is a side elevational view of the present design, a book rack;

FIG. 2 is rear elevational view of the book rack;

FIG. 3 is a top plan view of the book rack;

FIG. 4 is a side elevational view of the book rack;

FIG. 5 is an enlarged inverted perspective view of the book rack; and,

FIG. 6 is an enlarged upright perspective view of the book rack. 

The ornamental design for a book rack, as shown. 